Size segregation of granular materials during Paul-Wurth hopper charging and discharging process

Abstract

In an ironmaking blast furnace top, raw granular materials such as iron ore and coke are delivered to the parallel Paul-Wurth (PW) hoppers first and then discharged to the furnace. In this work, the effects of variables such as filling positions and filling angles on the size segregation during PW hopper charging and discharging processes are examined. Results illustrate that small particle gathering area appears near the filling points due to the rolling mechanism, and the area size is related to the distance of filling position to the side wall. Trajectory is another main segregation mechanism related to different filling angles. Steep filling angle changes particle trajectories significantly and large particles tend to gather in the side wall region. Increasing flow rate decreases the segregation. During the discharging process, a depression appears and large particles are engulfed in the depression, leading to the segregation at the last stage of discharging.